218 



HANDBOOK OF MECHANICAL DESIGN 



INQUIRY FORM FOR ELECTRIC MOTORS 



1. Name of machine to be driven- 



2. Field of use 



3. Estimated quantity, initial order — 

 first year 



4. Power supply: 



(a) Direct current volts 



(6) Alternating current 



phase, cj^cles 



_volts. 



(c) Universal motor_ 



_volts 



(d) Will power supply vary? 

 5. Motor speed and direction of rotation: 



(a) Full-load running speed I'.p.m. 



(b) Allowable variation + per cent of 



full-load speed 



(c) Direction of rotation, from end opposite 



shaft extension, clockwise , 



counter clockwise , reversible 



(d) Is a multispeed motor required? Give 

 speeds , , 



(e) Adjustable speed motor, speed range 

 to 



6. Running load requirements and conditions. 

 Load determined by test , ob- 

 tained from present practice , or 



estimated (For multispeed motor 



give following data for each speed) : 



(a) Continuous load hp. 



(6) Intermittent load hp. 



(1) length of time at full load 



min. 



(2) idle running min., time at 



rest min. 



(3) maximum momentary torque . 



lb in. 



(c) Fluctuating load 



(1) magnitude of overloads- 



(2) duration of overloads — 



(3) frequency of occurrence- 



(d) Reversing service 



(1) reversals per, min 



(2) time intervals on 



min. 



(3) inertia of load 



7. Starting load: 

 (a) Torque, starting 



_hp. 



_mm. 



i.,off 



-, accelerating 



(b) Is motor started under load?- 

 without load? 



(c) Type of unloading device 



(d) What is the inertia of the load including 

 couplings, pulleys, gear drives, or fly- 

 wheel ? 



(e) Speed of driven element r.p.m. 



(/) Drive: direct , gear , belt 



, chain_ 



if direct drive- 



Type of coupling 



8. Space available for motor : 



(a) Restricted to a maximum diameter of 



in. 



(6) Restricted to a maximum length of 



in. 



9. Motor mounting: 



(a) Vertical , horizontal , 



oblique 



(b) Foot mounting at end , below 



, above , flange mount- 



ing- 



Special (show by sketch) 



(c) Resilient mounting 



(d) Is mounting position of the motor 

 changeable ? 



10. Motor housing: 



(a) Motor exposure : outdoor , in- 

 door 



(6) Within machine or housing, partly in- 

 closed , totally inclosed 



(Give dimensioned sketch of housing and 

 show ventilation provisions) 



11. Condition of ventilating air: 



(a) Presence of dust , grit , 



moisture , steam , corrosive 



gases , oil vapor , explosive 



gas , salt air , other con- 

 tamination 



(5) Maximum temperature of cooling air 



deg. F. 



12. Bearings and lubrication: 



(a) Manufacturer's standard- 



(b) Motor to be lubricated at intervals of 



(c) End play restricted ; thrust loads 



present 



(d) Type of bearing preferred 



(1) Sleeve: lubricated by oil ring , " 



waste 



(2) Ball: lubricated by oil , or 



grease 



or 13. Shaft extension: single. 



_; if vertical, up 



.; straight or tapered 



or both ends 

 or down 



